/*
 Stream.cpp - adds parsing methods to Stream class
 Copyright (c) 2008 David A. Mellis.  All right reserved.

 This library is free software; you can redistribute it and/or
 modify it under the terms of the GNU Lesser General Public
 License as published by the Free Software Foundation; either
 version 2.1 of the License, or (at your option) any later version.

 This library is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 Lesser General Public License for more details.

 You should have received a copy of the GNU Lesser General Public
 License along with this library; if not, write to the Free Software
 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 Created July 2011
 parsing functions based on TextFinder library by Michael Margolis
 */

#include "Arduino.h"
#include <Stream.h>

#define PARSE_TIMEOUT 1000  // default number of milli-seconds to wait
#define NO_SKIP_CHAR 1      // a magic char not found in a valid ASCII numeric field

// private method to read stream with timeout
int Stream::timedRead() {
    int c;
    _startMillis = millis();
    do {
        c = read();
        if (c >= 0) {
            return c;
        }
    } while ((millis() - _startMillis) < _timeout);
    return -1;  // -1 indicates timeout
}

// private method to peek stream with timeout
int Stream::timedPeek() {
    int c;
    _startMillis = millis();
    do {
        c = peek();
        if (c >= 0) {
            return c;
        }
    } while ((millis() - _startMillis) < _timeout);
    return -1;  // -1 indicates timeout
}

// returns peek of the next digit in the stream or -1 if timeout
// discards non-numeric characters
int Stream::peekNextDigit() {
    int c;
    while (1) {
        c = timedPeek();
        if (c < 0) {
            return c;  // timeout
        }
        if (c == '-') {
            return c;
        }
        if (c >= '0' && c <= '9') {
            return c;
        }
        read();  // discard non-numeric
    }
}

// Public Methods
//////////////////////////////////////////////////////////////

void Stream::setTimeout(unsigned long timeout)  // sets the maximum number of milliseconds to wait
{
    _timeout = timeout;
}
unsigned long Stream::getTimeout(void) {
    return _timeout;
}

// find returns true if the target string is found
bool Stream::find(const char* target) {
    return find(target, strlen(target));
}

// reads data from the stream until the target string of given length is found
// returns true if target string is found, false if timed out
bool Stream::find(const char* target, size_t targetLen) {
    int targetIdx = 0;
    while (targetIdx < targetLen) {
        auto current = read();
        if (current == target[targetIdx]) {
            ++targetIdx;
        } else {
            targetIdx = 0;
        }
    }
    return targetIdx == targetLen;
}

/*
// as find but search ends if the terminator string is found
bool Stream::findUntil(const char* target, const char* terminator) {
    return findUntil(target, strlen(target), terminator, strlen(terminator));
}

// reads data from the stream until the target string of the given length is found
// search terminated if the terminator string is found
// returns true if target string is found, false if terminated or timed out
bool Stream::findUntil(const char* target, size_t targetLen, const char* terminator, size_t termLen) {
    if (terminator == NULL) {
        MultiTarget t[1] = { { target, targetLen, 0 } };
        return findMulti(t, 1) == 0 ? true : false;
    } else {
        MultiTarget t[2] = { { target, targetLen, 0 }, { terminator, termLen, 0 } };
        return findMulti(t, 2) == 0 ? true : false;
    }
}

int Stream::findMulti(struct Stream::MultiTarget* targets, int tCount) {
    // any zero length target string automatically matches and would make
    // a mess of the rest of the algorithm.
    for (struct MultiTarget* t = targets; t < targets + tCount; ++t) {
        if (t->len <= 0)
            return t - targets;
    }

    while (1) {
        int c = timedRead();
        if (c < 0)
            return -1;

        for (struct MultiTarget* t = targets; t < targets + tCount; ++t) {
            // the simple case is if we match, deal with that first.
            if (c == t->str[t->index]) {
                if (++t->index == t->len)
                    return t - targets;
                else
                    continue;
            }

            // if not we need to walk back and see if we could have matched further
            // down the stream (ie '1112' doesn't match the first position in '11112'
            // but it will match the second position so we can't just reset the current
            // index to 0 when we find a mismatch.
            if (t->index == 0)
                continue;

            int origIndex = t->index;
            do {
                --t->index;
                // first check if current char works against the new current index
                if (c != t->str[t->index])
                    continue;

                // if it's the only char then we're good, nothing more to check
                if (t->index == 0) {
                    t->index++;
                    break;
                }

                // otherwise we need to check the rest of the found string
                int    diff = origIndex - t->index;
                size_t i;
                for (i = 0; i < t->index; ++i) {
                    if (t->str[i] != t->str[i + diff])
                        break;
                }

                // if we successfully got through the previous loop then our current
                // index is good.
                if (i == t->index) {
                    t->index++;
                    break;
                }

                // otherwise we just try the next index
            } while (t->index);
        }
    }
    // unreachable
    return -1;
}
*/

// returns the first valid (long) integer value from the current position.
// initial characters that are not digits (or the minus sign) are skipped
// function is terminated by the first character that is not a digit.
long Stream::parseInt() {
    return parseInt(NO_SKIP_CHAR);  // terminate on first non-digit character (or timeout)
}

// as above but a given skipChar is ignored
// this allows format characters (typically commas) in values to be ignored
long Stream::parseInt(char skipChar) {
    bool isNegative = false;
    long value      = 0;
    int  c;

    c = peekNextDigit();
    // ignore non numeric leading characters
    if (c < 0) {
        return 0;  // zero returned if timeout
    }

    do {
        if (c == skipChar) {
        }  // ignore this character
        else if (c == '-') {
            isNegative = true;
        } else if (c >= '0' && c <= '9') {  // is c a digit?
            value = value * 10 + c - '0';
        }
        read();  // consume the character we got with peek
        c = timedPeek();
    } while ((c >= '0' && c <= '9') || c == skipChar);

    if (isNegative) {
        value = -value;
    }
    return value;
}

// as parseInt but returns a floating point value
float Stream::parseFloat() {
    return parseFloat(NO_SKIP_CHAR);
}

// as above but the given skipChar is ignored
// this allows format characters (typically commas) in values to be ignored
float Stream::parseFloat(char skipChar) {
    bool  isNegative = false;
    bool  isFraction = false;
    long  value      = 0;
    int   c;
    float fraction = 1.0;

    c = peekNextDigit();
    // ignore non numeric leading characters
    if (c < 0) {
        return 0;  // zero returned if timeout
    }

    do {
        if (c == skipChar) {
        }  // ignore
        else if (c == '-') {
            isNegative = true;
        } else if (c == '.') {
            isFraction = true;
        } else if (c >= '0' && c <= '9') {  // is c a digit?
            value = value * 10 + c - '0';
            if (isFraction) {
                fraction *= 0.1;
            }
        }
        read();  // consume the character we got with peek
        c = timedPeek();
    } while ((c >= '0' && c <= '9') || c == '.' || c == skipChar);

    if (isNegative) {
        value = -value;
    }
    if (isFraction) {
        return value * fraction;
    } else {
        return value;
    }
}

// read characters from stream into buffer
// terminates if length characters have been read, or timeout (see setTimeout)
// returns the number of characters placed in the buffer
// the buffer is NOT null terminated.
//
size_t Stream::readBytes(char* buffer, size_t length) {
    size_t count = 0;
    while (count < length) {
        int c = timedRead();
        if (c < 0) {
            break;
        }
        *buffer++ = (char)c;
        count++;
    }
    return count;
}

// as readBytes with terminator character
// terminates if length characters have been read, timeout, or if the terminator character  detected
// returns the number of characters placed in the buffer (0 means no valid data found)

size_t Stream::readBytesUntil(char terminator, char* buffer, size_t length) {
    if (length < 1) {
        return 0;
    }
    size_t index = 0;
    while (index < length) {
        int c = timedRead();
        if (c < 0 || c == terminator) {
            break;
        }
        *buffer++ = (char)c;
        index++;
    }
    return index;  // return number of characters, not including null terminator
}

String Stream::readString() {
    String ret;
    int    c = timedRead();
    while (c >= 0) {
        ret += (char)c;
        c = timedRead();
    }
    return ret;
}

String Stream::readStringUntil(char terminator) {
    String ret;
    int    c = timedRead();
    while (c >= 0 && c != terminator) {
        ret += (char)c;
        c = timedRead();
    }
    return ret;
}
